The Institute of Electrical and Electronics Engineers (IEEE) 802.11ac amendment to the IEEE 802.11 standard is the next-generation wireless local area network (WLAN) enhancement that is highly anticipated by the wireless industry. The 802.11ac amendment is designed to provide a significant increase in achievable data rates.
A new feature introduced by the IEEE 802.11ac amendment is operation in channel-widths of 80 MHz, 160 MHz and 80+80 MHz. These channels are significantly wider than the current 20 or 40 MHz wide channels of IEEE 802.11n. Consequently, dynamic channel assignment schemes need to handle and optimize to the new wider channelizations of IEEE 802.11ac, yet account for the coexistence with legacy devices that operate according to the 802.11n standard.
In addition, 802.11ac also allows an access point (AP) to switch from the wider channel-width modes to one of the existing narrower bandwidths, such as 20 MHz or 40 MHz. This is particularly useful for networks that have 802.11ac APs along with legacy APs and/or clients, which can only operate with the narrower bandwidths. While an AP should switch modes whenever it is more beneficial for performance, the exact conditions for doing so are not specified in the standard.